Tri-mode locomotive

ABSTRACT

A locomotive consist including a pair of fuel-electric locomotives, each having a prime mover engine and a power transmission system including a main generator and traction motors coupled to driving wheels, a high voltage electrical connection operable in an on state or an off state, and a computer controller. The pair of fuel-electric locomotives is configured to selectively cooperate to operate in three different operating modes as controlled by the computer controller: (1) a prime mover mode, (2) a mother/slug mode, and a mother/inoperative mode.

FIELD

This disclosure relates to the field of fuel-electric locomotives. Moreparticularly, the disclosure relates to fuel-electric locomotives ofimproved construction and configured to have multiple operational modesfor use in a consist for enhanced fuel efficiency, reduced operatingcosts, reduced maintenance, and reduced emissions.

BACKGROUND

Improvement is desired in construction and operation of fuel-electriclocomotives. What is desired is a locomotive system configured to reduceoperation time of the collective associated fuel engines to improve fueleconomy, reduce emissions, and lower maintenance and other operationalcosts.

Each fuel-electric locomotive in a conventional locomotive consistalways has its prime mover engine operating. Each trailing locomotive ofthe consist is operated in the same manner as the lead locomotive by amultiple-unit train controller (MU controller) and connection and anassociated air-line for the brakes. An engineer operates the leadlocomotive and a control signal is sent to each trailing locomotive sothat each trailing locomotive operates the same as the lead locomotive.Thus, the prime mover engine setting for each trailing locomotive isalways the same as the prime mover engine setting for the leadlocomotive. For a majority of the operation of the consist the extrahorsepower represented by the operation of the prime mover engines ofthe trialing locomotives is not utilized and represents waste.

A conventional railroad slug is an accessory to a fuel-electriclocomotive. It has traction motors but, unlike a conventionallocomotive, it cannot generate power on its own since it lacks a primemover engine. Instead, the slug is connected to a powered locomotive,called the mother. The MU controller of the mother locomotive providesthe needed electrical power to operate the traction motors via a highvoltage connection, and the traction motor controls via a separate slugcontrol connection. The air-line of the mother locomotive provides airfor braking.

Accordingly, in a conventional consist having two locomotives, eachlocomotive is operated identically and both fuel engines are alwaysoperating. This is the case even if a slug is added. This representsconsiderable waste of fuel, engine operating time and its associatedmaintenance, and increased emissions, all of which are undesirable.

The present disclosure advantageously provides improved fuel-electriclocomotives that have additional modes of operation and cooperate toreduce the net operating time of the collective fuel engines of theconsist. That is, in a consist having a pair of the locomotives of thedisclosure, the prime mover engines can be independently operated sothat the prime mover engine of the trailing locomotive can be turned offand not have to run all the time that the prime mover engine of the leadlocomotive is on. This improves fuel economy, reduces emissions andmaintenance, and lowers operational costs as compared to use ofconventional locomotives. Better fuel economy is achieved by running asingle engine at a higher RPM when the turbos and engine efficienciesare at its highest.

For example, in accordance with the disclosure, a two locomotive consistcan be provided and operated so that it is not requisite to have theengine of the trailing locomotive operating at all times. Thisrepresents considerable fuel savings, reductions in maintenance, andreductions in emissions.

Further, if a slug is added to a conventional two locomotive consist,the slug represents an additional equipment cost. The present disclosureprovides a two locomotive consist that is able to operate in amother/slug configuration with only the two locomotives. This representsconsiderable reductions in costs and maintenance.

SUMMARY

The above and other needs are met by improved locomotive consists andlocomotives.

In one aspect, a locomotive consist according to the disclosure includesa pair of fuel-electric locomotives. Each fuel-electric locomotive has aprime mover engine and a power transmission system including a maingenerator and traction motors coupled to driving wheels, a high voltageelectrical connection operable in an on state or an off state, and acomputer controller. The pair of fuel-electric locomotives is configuredto selectively cooperate to operate in three different operating modesas controlled by the computer controller.

One of the operating modes is a prime mover mode in which the primemover engine of each of the fuel-electric locomotives is on and used tooperate its own main generator to make power for its own tractionmotors, and the high voltage electrical connection is in the off state.

Another operating mode is a mother/slug mode in which the prime moverengine of one of the locomotives is off, the high voltage electricalconnection is in the on state, and the prime mover engine of the otherlocomotive is on and used to operate its own generator to supply powerfor its traction motors, and to also supply power to the traction motorsof the other locomotive whose prime mover engine is off.

A further operating mode is a mother/inoperative mode in which the primemover engine of one of the locomotives is off, the high voltageelectrical connection is in the off state, and the prime mover engine ofthe other locomotive is on and used to operate its own generator tosupply power for its traction motors and does not supply power to thetraction motors of the other locomotive.

In another aspect, a fuel-electric locomotive according to thedisclosure includes a prime mover engine and a power transmission systemincluding a main generator and traction motors coupled to drivingwheels, a high voltage electrical connection, and a computer controller,

The locomotive is selectively operable as: (a) a prime mover locomotivein which the prime mover engine of the locomotive is operating and usedto operate the generator to make power for operation of thefuel-electric locomotive; (b) a mother locomotive in which the primemover engine is operating and used to operate the generator to makepower for operation of the fuel-electric locomotive and also providespower to another locomotive; (c) a slug in which the prime mover engineis not operating and the locomotive receives power from anotherlocomotive to power the traction motors; and (d) an inoperativelocomotive in which the prime mover engine is not operating and thelocomotive does not receive power from another locomotive to power thetraction motors.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the disclosure are apparent by reference to thedetailed description when considered in conjunction with the figures,which are not to scale so as to more clearly show the details, whereinlike reference numbers indicate like elements throughout the severalviews, and wherein:

FIGS. 1A and 1B depict a prime mover operational mode for a pair oftri-mode locomotives according to the disclosure, and FIG. 1C showsconnections between the locomotives.

FIGS. 2A and 2B depicts a mother/slug operational mode for the pair oftri-mode locomotives.

FIGS. 3A and 3B depict a mother/inoperative operational mode for thepair of tri-mode locomotives.

DETAILED DESCRIPTION

With initial reference to FIGS. 1A and 1B, there is shown a train orlocomotive consist 10 having two identically and specially configuredfuel-electric locomotives 12 and 14.

The locomotives 12 and 14 are configured to be able to operate in threedifferent modes: (1) a prime mover mode; (2) a mother/slug mode; and (3)a mother/inoperative mode. Thus, each of the locomotives 12 and 14 canoperate as a prime mover locomotive, a mother locomotive, a slug, and aninoperative locomotive.

FIGS. 1A and 1B depicts the prime mover mode. When the consist 10 isoperating in the prime mover mode the diesel or other fuel engines ofboth of the locomotives 12 and 14 are on.

In the mother/slug mode only the diesel engine of one of the locomotives12/14 is on and this locomotive serves as a mother. The other locomotiveserves as a slug and the mother provides power for the drive wheels ofboth locomotives.

In the mother/inoperative mode, only the diesel engine of one of thelocomotives 12/14 is on and this locomotive serves as the mother. Theother locomotive serves as an inoperative locomotive. In this mode themother powers only its own the drive wheels.

As will be noted, the fuel-engines of the locomotives 12 and 14 both areon only in the prime mover mode. In the mother/slug mode and in themother/inoperative mode only the fuel-engine of the mother locomotive ison. The consist 10 having the locomotives 12 and 14 may thus be operatedin a manner that diverges significantly from the operation of aconventional consist and achieve substantial savings in fuel,maintenance, and other costs.

In this regard, the consist 10 of the disclosure enables substantialsavings in fuel and maintenance as compared to a conventional consisthaving conventional locomotives and conventional slugs. For example, ina conventional consist in which the locomotives all have their enginesoperating there is considerable time during the operation when theconsist does not require all of the power output by the engines of thelocomotives. This represents considerable waste in fuel and hours ofengine operation which result in engine wear and engine maintenance.

The consist 10 may be a freight train or passenger train and includeadditional non-powered cars that the locomotives 12 and 14 pull or pushto provide the consist 10. The consist 10 as described herein includesthe locomotives 12 and 14 as a pair of locomotives in the consist 10. Itis contemplated that the consist 10 may include additional locomotivesincluding additional pairs of the locomotives 12 and 14.

Each of the locomotives 12 and 14 has a prime mover engine 16 and apower transmission system 18 including a main generator 18 a, tractionmotors 18 b geared to driving wheels 18 c.

The locomotives 12 and 14 further include a high voltage electricalconnection 20, an MU controller 22, and an auxiliary controller 22 a.The locomotives 12 and 14 each also include a cab 24 within which anengineer is located when the locomotive 12 and/or 14 is the leadlocomotive of the locomotive consist 10.

With reference to FIG. 1C, the locomotives 12 and 14 are physicallyconnected to one another via cooperating conventional railway couplings30. In addition to the high voltage connection 20, the locomotives 12and 14 also have an air-line 32 and electrical connections in the formof a MU connection 34, an electrical connection for traction motorcooling air motors 36, and a slug control connection 38.

Conventional locomotives have the railway couplings 30, the air-line 32,and the MU connection 34. A conventional locomotive connected to aconventional slug will also have the high voltage connection 20 and theslug control connection 38.

Conventional locomotives lack the auxiliary controller 22 a and themultiple operational features of the locomotives 12 and 14 of thedisclosure. Conventional locomotives also lack the electrical connectionfor traction motor cooling air motors 36, as described more fully below.

The prime mover engine 16 is a conventional locomotive fuel engine,either a diesel or gasoline engine suitable to power the locomotive 12or 14 as a primary locomotive. The prime mover engine 16 rotates themain generator 18 a which produces electricity to power the tractionmotors 18 b that are geared to the driving wheels 18 c.

The power transmission system 18 electrically connects the prime moverengine 16 to the driving wheels 18 c, as there is no mechanicalconnection between the prime mover engine 16 and the driving wheels 18c.

The main generator 18 a of the power transmission system 18 may beprovided by a conventional locomotive DC generator or a conventionallocomotive electrical AC alternator-rectifier. In either case, whetherthe main generator 18 a is outputting direct current or alternatingcurrent, the output provides power to the traction motors 18 b.

The traction motors 18 b and driving wheels 18 c are conventional AC orDC electric motors and driving wheels used for propulsion of afuel-electric locomotive. The motors 18 b include conventional coolingdevices such as cooling fans for cooling the motors during operation.

With reference to FIGS. 1A and 1B, when the consist 10 is operating inprime mover mode, both the locomotives 12 and 14 will be in prime movermode. This is characterized by the engines 16 of both the locomotive 12and the locomotive 14 being operated and each of the engines 16 isexclusively used to operate its own generator 18 a to make power for itsown traction motors 18 b, and the high voltage electrical connection 20is in an Off state and power is not supplied from the lead locomotive topower the traction motors 18 b of the trailing locomotive and theirassociated cooling fans.

FIGS. 2A and 2B depict the consist 10 operating in mother/slug mode,with the lead locomotive serving as a mother and the trailing locomotiveserving as a slug. As shown, the high voltage connections 20 are in aconnected state so that the generator 18 a of the lead locomotive isalso able to supply electrical power to the traction motors 18 b of thetrailing locomotive. Only the fuel-engine 16 of the mother locomotive ison.

With further reference to FIGS. 2A and 2B, during operation of theconsist 10 in the mother/slug mode, it will be appreciated that at lowspeeds the lead or mother locomotive can develop substantially morepower than it needs for the operation of its own traction motors 18 b.Thus, the surplus power may be sent to the trailing or slug locomotive,which does not have its engine 16 turned on, to provide electrical powerfor the traction motors 18 b of the trailing locomotive that is in theslug mode via the high voltage connections 20.

With reference to FIGS. 3A and 3B, the mother/inoperative mode is thesame as the mother/slug mode, except the high voltage electricalconnection 20 is in an off state or disconnected state and power is notsupplied from the lead locomotive to power the traction motors 18 b ofthe trailing locomotive.

The consist 10 can transition between the various modes as needed. Forexample, if the consist 10 is operating in prime mover mode ormother/slug mode, if the consist 10 slows its speed or reaches a pointthat the extra power from operation of the traction motors 18 b of thetrailing locomotive is not needed, the consist 10 will transition to themother/inoperative mode. As noted above, in the mother/inoperative modethe fuel engine 16 of the inoperative locomotive is off and the highvoltage connections 20 are disconnected.

However, in the mother/inoperative mode, the traction motors 18 b of thetrailing/inoperative locomotive are not powered but are operative toprovide dynamic braking. Dynamic braking is the use of an electrictraction motor as a generator when slowing the consist 10. However,dynamic braking generates heat and the traction motors 18 b can overheatif their associated cooling devices such as cooling fans are notoperated. Thus, the electrical connection for traction motor cooling airmotors 36 is utilized in the mother/inoperative mode to provideelectrical power to operate cooling fans associated with the otherwiseunpowered traction motors 18 b of the trailing locomotive. Theelectrical connection for traction motor cooling air motors 36 isdesirably a three phase AC connection between the locomotives 12 and 14.

As noted, the consist 10 is advantageously configured to enable fluidtransition between the various modes based on power needs of the consist10. For example, when the consist 10 is operating in themother/inoperative mode, if the auxiliary controller 22 a senses thatextra power is needed for the consist 10, the consist 10 will transitionback to the mother/slug mode or the prime mover mode as needed, andreturn to the mother/inoperative mode when the need for extra power isnot needed. These transitions between the modes are controlled by theauxiliary controllers 22 a to happen repeatably as needed during travelof the consist 10 to minimize operation of the traction motors 18 b ofthe trailing locomotive.

In this regard, the auxiliary controller 22 a of the lead locomotiveoperates the locomotives 12 and 14 in a manner to more efficientlyoperate the consist 10 and to minimize the operation of the engines 16,which represents associated fuel usage and emissions. The auxiliarycontrollers 22 a include software operative to automatically changebetween the modes (prime mover/prime mover, mother/slug,mother/inoperative) as required for efficient operation of thelocomotives 12 and 14.

As further example, as the consist 10 picks up speed during operation inthe mother/slug mode, the amount of surplus power available from theengine 16 of the lead locomotive declines. When the speed of the consist10 is at about 10 to 12 miles per hour it is typical that the leadlocomotive needs all of the power it generates from operation of itsengine 16 for its own traction motors 18 b to increase the speed of theconsist 10. Thus, at this point it is desirable to disconnect the highvoltage connection 20 and operate the consist 10 in themother/inoperative mode as shown in FIGS. 3A and 3B.

As will be further noted, in both the mother/slug mode and themother/inoperative mode, the engine 16 of the trailing locomotive isoff, thereby saving fuel, maintenance, and reducing emissions.

During operation of the consist 10 in the mother/slug mode or themother/inoperative mode, if it is sensed by the controller 22 a of thelead locomotive that the power produced by engine 16 of the leadlocomotive is insufficient to continue to accelerate the consist 10, theauxiliary controller 22 a will send a signal to start the engine 16 ofthe trailing locomotive and return the consist 10 to the prime movermode of FIGS. 1A and 1B.

Thus, as shown by the foregoing examples, the consist 10 may be operatedin a manner to reduce the amount of time that the consist 10 has both ofthe locomotives 12 and 14 in prime mover mode. Thus, for thecircumstance where the consist 10 has changed from the mother/slug modeto the prime mover mode, if the auxiliary controller 22 a detects thatthe power of the trailing locomotive is not needed, as for example whenthe consist 10 goes downhill, the engine 16 of the trailing locomotiveis automatically turned off again and the locomotive reverts back to themother/inoperative mode with the high voltage connection 20 remainingdisconnected.

This state of operation remains unless and until the auxiliarycontroller 22 a of the lead locomotive determines that additional poweris needed. In such case, the electrical connection 20 is placed in aconnected state and electrical power is supplied from the trailinglocomotive to the traction motors 18 b of the trailing locomotive toreturn the consist 10 to the mother/slug mode. Likewise, if the powerfrom both of the engines 16 is needed, the consist 10 returns to theprime move mode.

While not required, it is desirable to operate the locomotives 12 and 14with predictive software so that the consist 10 can be operated inmother/slug mode and mother/inoperative mode at optimum times during thetrip. For example, the predictive software would determine, andautomatically operate, the software associated with the auxiliarycontrollers 22 a to turn the power off to the trailing locomotive at theoptimum time before the consist 10 reaches the top of a hill or to turnit on at the optimum time as it approaches a hill.

Either or both of the locomotives 12 and 14 may also be used alone as aconventional locomotive, and can be used to power a conventional slug.The locomotives 12 and 14 may also operate in a multiple locomotiveconsist with conventional locomotives or become part of a distributedpower arrangement either as a single locomotive or together as describedwith the tri-mode features.

Accordingly, the present device advantageously provides an improvedlocomotive system configured to reduce operation time of the associatedfuel engines and traction motors to improve fuel economy, reduceemissions, and lower operational costs. The locomotives areadvantageously configured to have multiple operational modes (primemover mode, mother mode, slug mode, and inoperative mode) for use in aconsist for enhanced fuel efficiency and reduced emissions.

The foregoing description of preferred embodiments for this disclosurehas been presented for purposes of illustration and description. It isnot intended to be exhaustive or to limit the disclosure to the preciseform disclosed. Obvious modifications or variations are possible inlight of the above teachings. The embodiments are chosen and describedin an effort to provide the best illustrations of the principles of thedisclosure and its practical application, and to thereby enable one ofordinary skill in the art to utilize the disclosure in variousembodiments and with various modifications as are suited to theparticular use contemplated. All such modifications and variations arewithin the scope of the disclosure as determined by the appended claimswhen interpreted in accordance with the breadth to which they arefairly, legally, and equitably entitled.

The invention claimed is:
 1. A locomotive consist, comprising: a pair offuel-electric locomotives, each fuel-electric locomotive having a primemover engine and a power transmission system including a main generatorand traction motors coupled to driving wheels, a high voltage electricalconnection operable in an on state or an off state, and a computercontroller, with the pair of fuel-electric locomotives configured toselectively cooperate to operate in three different operating modes ascontrolled by the computer controller, the operating modes comprising:(a) a prime mover mode in which the prime mover engine of each of thefuel-electric locomotives is on and used to operate its own maingenerator to make power for its own traction motors, and the highvoltage electrical connection is in the off state; (b) a mother/slugmode in which the prime mover engine of one of the locomotives is off,the high voltage electrical connection is in the on state, and the primemover engine of the other locomotive is on and used to operate its owngenerator to supply power for its traction motors, and to also supplypower to the traction motors of the one locomotive whose prime moverengine is off; and (c) a mother/inoperative mode in which the primemover engine of one of the locomotives is off, the high voltageelectrical connection is in the off state, and the prime mover engine ofthe other locomotive is on and used to operate its own generator tosupply power for its traction motors and does not supply power to thetraction motors of the other locomotive.
 2. The locomotive consist ofclaim 1, further comprising an electrical connection operative in themother/inoperative mode to supply electrical power during dynamicbraking to cooling fans associated with the traction motors of thelocomotive whose prime mover engine is off.
 3. The locomotive consist ofclaim 1, wherein each of the fuel-engine locomotives includes a railwaycoupling, an air-line, an MU connection, a slug control connection, andan electrical connection for traction motor cooling air motors.
 4. Thelocomotive consist of claim 1, wherein when the consist is in themother/slug mode or the mother/inoperative mode and moving solely underpower supplied by the prime mover engine of one of the locomotives, thecomputer controller is operative to determine when the power supplied bythe prime mover engine that is on is insufficient to continue toaccelerate the consist, and the computer controller operates to turn onthe other prime mover engine and transition the consist to the primemover mode.
 5. A fuel-electric locomotive, comprising: a prime moverengine and a power transmission system including a main generator andtraction motors coupled to driving wheels, a high voltage electricalconnection, and a computer controller, wherein the locomotive isselectively operable as: (a) a prime mover locomotive in which the primemover engine of the locomotive is operating and used to operate thegenerator to make power for operation of the fuel-electric locomotive;(b) a mother locomotive in which the prime mover engine is operating andused to operate the generator to make power for operation of thefuel-electric locomotive and also provides power to another locomotive'straction motors; (c) a slug in which the prime mover engine is notoperating and the locomotive receives power from another locomotive topower the traction motors; and (d) an inoperative locomotive in whichthe prime mover engine is not operating and the locomotive does notreceive power from another locomotive to power the traction motors. 6.The locomotive of claim 5, wherein the fuel-electric locomotive furtherincludes an electrical connection for traction motor cooling air motorsand when operating as an inoperative locomotive the electricalconnection for traction motor cooling air motors provides electricalpower during dynamic braking to cooling fans associated with thetraction motors thereof.